Machines for operating on shoe parts



Sept. 3, 1968 l F. T. MaCKENzIE ETAL 3,399,410

MACHINES FOR OPERATING ON SHOE PARTS Filed Feb. l, 1967 6 Sheets-Sheet l o Jag! Q Q Q s) Q @3 @D C@ Q /52 W f /22 W Fred Z Mac Kenz/'e Haro/d J. Tabbu uw a zzyzf/ Sept. 3, 1968 F. r. MacKENzn-z ETAL 3,399,410

MACHINES FOR OPERATING ON SHOE PARTS I e Sheets-Sheet 2 Filed Feb. l, 1967 Sept. 3, 1968 F. T. MacKENzlE ETAL 3,399,410

MACHINES FOR OPERATING ON SHOE PARTS Filed Feb. l, 1967 6 Sheets--Sheei'l 5 Sept. 3, 1968 F. T. MaoKENzIE ETAL 3,399,410

MACHINES FOR OPERATING ON SHOE PARTS 6 Sheets-Sheet 4 Filed Feb. l, 1967 Sept. 3, 1968 F. T. MaCKENzlE ETAL MACHINES FOR OPERATING ON SHOE PARTS Filed Feb. l, 1967 6 Sheetsheet 5 F. T. MaCKENzlE ETAL 3,399,410

MACHINES FOR OPERATING ON SHOE PARTS Sept. 3, 196s 6 Sheets-Sheet 6 Filed Feb. l, 1967 Jag@ .,f, @f W D M 5? i O L C LM Wm w M m f f m -A f w m m 1 I ----2 kftkmfllmww r I I l i I I l |m`fllllllmllll mlVllll A rlf........M.- 2m y 2m r l l l v I 1 A l l l l n x l l n 1 l l 1 l x x l l l I 1 l l l l l l xifll United States Patent O 3,399,410 MACHINES FOR OPERATING ON SHOE PARTS Fred T. MacKenzie and Harold J. Tabbut, Beverly, Mass., assignors to United Shoe Machinery Corporation, Flemington, NJ., a corporation f New Jersey Filed Feb. 1, 1967, Ser. No. 613,343 21 Claims. (Cl. 12-1) ABSTRACT OF THE DISCLOSURE A machine for operating on shoe parts having a work supporting table and instrumentalities for operating on a shoe part thereon, is provided with a shoe part handling mechanism having a pick-up device for automatically placing shoe parts, picked up from a stacking device, oneby-one on the work table, for initiating an automatic operating cycle of the machine, and for removing each part from the table after it has been operated on by the machine, and depositing it on a shoe part receiving device.

Background of the invention This invention relates to machines for operating on shoe parts and is especially concerned with a novel and improved mechanism for handling shoe parts by picking them up, one-by-one, placing them in a machine to be operated on and then removing them from the machine following its loperation on the shoe part. While herein illustrated as associated with a machine for applying molten thermoplastic material to the vamp portion of a shoe upper of the type disclosed and -claimed in U.S Letters Patent No. 3,277,867 issued Oct. ll, 1966, on an application tiled Mar. 3l, 1964, in the names of Charles O. Kilham and Roscoe L. Hill, it is to be understood that the invention in its broader aspects is not limited to use with a machine of this particular type yor to the exact mechanical construction shown.

In the manufacture of shoes, or more particularly in the production of the diierent parts of which shoes are made, various machines are utilized which, like the machine referred to above, have operating elements, a work table or the like and mechanism operable in an automatic operating cycle to cause a shoe part placed on the table t-o be presented to the operating elements, the elements to perform their operation on the shoe part and the table to be returned to a starting'position. In using machines of this type, the `operator is required to pick up a shoe part, place it on the table, initiate an automatic operating cycle of the machine, as by stepping on a treadle, or pushing a button, and to remove the shoe part from the table after the machine has operated on it and the table has been returned to its starting position. This simple and monotonous process is repeated over and over again until the entire lot of shoe parts has been operated on by the machine.

Summary of the invention It is the primary object of this invention to avoid the need for employment of a human operator in the performance of such a simple task, and at the same time to save labor costs and to eliminate human errors, by providing mechanical means capable -of handling shoe parts by placing them in and removing them from the machine in an efficient and wholly reliable manner, With this object in view and in accordance with features of the invention, the herein illustrated machine is of the type referred to above, and has elements for operating on shoe parts, a work table and mechanism operating in an automatic cycle for effecting relative movements of the operating elements and the table to cause the shoe part thereon to Patented Sept. 3, 1968 be presented to the operating elements, these elements to operate on the shoe part and the table to return to a starting position. Provided in combination with these elements is a novel shoe part handling mechanism adapted to place shoe parts, successively, on the table, to initiate'an automatic operating cycle of the machine and to remove the shoe part from the table after the table has returned to a starting position.

More particularly, the shoe part handling mechanism includes a shoe part stacking device, a shoe part receiving device and a pair of shoe part handling members each comprising a vacuum pick-up device mounted for swinging movement about an axis perpendicular to the plane of the work table. `Means are provided for causing one of the pick-up devices to pick up the uppermost shoe part from a stack of shoe parts on the stacking device, place it on the work table of the machine, initiate an automatic operating cycle of the machine and for causing the other pick-up device t-o pick up the shoe part from the table and deposit it on the shoe part receiving device. The shoe part stacking device is mounted for reciprocating movement to present the uppermost shoe part thereon to the first-mentioned shoe part handling member and power operated means are provided for reciprocating the stacking device together with control means. Said control means includes a sensing member, operative independently of the pick-up member and movable relative thereto, adapted to being contacted by the uppermost shoe part tor arresting the upward movement 4of the stacking device. The control means also includes a time delay device for varying the interval Ibetween movement of the sensing member and the arresting of the movement of the stacking device and is operable to interrupt the operation of the shoe part handling mechanism prior t-o the initiation of an automatic operating cycle of the machine when no shoe part is picked up by the shoe part handling mechanism or is placed on the work table by said mechanism.

These and other objects and features of the invention will appear in the following detailed description of the embodiment illustrated in the accompanying drawings and will be pointed out in the claims.

In the drawings:

FIG. l is a View, in perspective, of a thermoplastic box toe applying machine to which there has been applied an automatic loading and unloading mechanism embodying the features of this invention;

FIG. 2 is a plan view, on an enlarged scale of a portion of the box toe applying machine shown in FIG. l and showing the two operating elements of the loading and unloading mechanism in one of the positions assumed during its operation;

FIG. 3 is a plan View similar to that of FIG. 2 but showing one of the elements of the automatic loading mechanism in a'ditterent operating position;

FIG. 4 is also a plan View similar to FIG. 2 but showing the other of the two operating elements in a different operating position;

FIG. 5 is a plan view similar to that of FIG. 2 but showing the mechanism for -actuating the two operating elements of the loading and unloading mechanism, this mechanism having been omitted from FIG. 2 in order to simplify its disclosure;

FIG. 6 is a view in front elevation of another part of the automatic loading and unloading mechanism;

FIG. 7 is a detail view of a part of the work supporting mechanism of the machine;

FIG. 8 is a diagram of the pneumatic operating system; and

FIG. 9 is an electrical diagram.

Referring to these drawings, land particularly to FIG. l, the machine therein illustrated is basically the same as the machine disclosed and claimed in the patent referred to above. Thus, this machine has a work table and a clamp member 22 adapted to be moved relatively to each other by means of a fluid actuated piston 24 contained within a cylinder 26, FIG. 7, to effect a clamping of a shoe part, herein illustrated as the vamp portion of a shoe upper, between the clamp member and a pad 28, mounted on the work table, see FIGS. 2, 3 and 7, generally in the same manner as in the machine of the mentioned application. However, in the herein illustrated construction, the pad 28, which provides the shoe part supporting surface of `the work table, is yieldingly mounted thereon by means of four coil springs 21, one of which appears in FIG. 7, which hold the pad yieldingly in a predetermined uppermost position. Also, when the piston 24 is operated, the pad is pulled downwardly through pressure exerted by the clamp member 22 on the shoe part placed on the pad, this clamp member moving downwardly to a definite position as determined by the engagement of the lower surface 23 of the clamp member with a surface 25 on the work table. Thus, the uppermost surface of the pad 28 will always lie in the same horizontal plane (see X-X, FIG. 7) when there is no shoe part clamped thereagainst, while the uppermost surface of a shoe part clamped thereon always lies in another predetermined horizontal plane corresponding to the lower surface of the clamp member 22, regardless of the thickness of the shoe part, see broken line Z-Z, FIG. 7. Also, the work table 20 is mounted for reciprocating movement, by means of a piston 30 contained within a cylinder 32, FIG. 7, to present a work piece clamped thereon to the action of an applicator device, indicated generally by the reference character 40. As in the prior construction disclosed in the above-mentioned patent, this device includes a roll for applying a molten thermoplastic material on that portion of the vamp left exposed above the clamp member 22, when the device is moved downwardly to bring the `roll in engagement with -the exposed portion of the vamp by means of a piston contained within a cylinder 52, FIG. 7.

The arrangement is such that in response to `the initiation of an :automatic operating cycle, as is explained in the mentioned patent, a vamp portion V of an upper placed on the pad 28 and beneath the clamp member 22 by the operator is clamped between the work table 20 and the clamp member 22 as a result of relative movement between these parts; the work table is moved inwardly to carry the vamp beneath the applicator device; the applicator device is lowered to bring its role into engagement with the exposed surface of the vamp, the table is moved outwardly and Iduring such outward movement of the table the roll applies a layer of molten thermoplastic material on the exposed portion of the vamp and finally the applicator device is elevated to complete `the operating cycle. These various functions -of the work clamping, table movement and applicator lowering and raising, are effected by the pistons 24, 30 and 50 in a predetermined sequence controlled by various pilot operated valves, sequence valves, etc., to be referred to below and forming a pneumatic operating system diagrammatically illustrated in the lower portion of FIG. 7. Inasmuch as this pneumatic operating system, although somewhat more sophisticated, is essentially the same as that disclosed and described in detail in the above-mentioned application, to which reference may be made, it is deemed unnecessary to describe it here in detail.

In accordance with the present invention, the vamp portions are automatically placed on the work table and, following an automatic operating cycle similar to that outlined in the preceeding paragraph, are removed therefrom by means of mechanism now to be described. As shown in FIG. 1, the box toe applying machine is supported on an enclosed frame construction, indicated generally by the reference character 100, and is provided with a horizontally extending platform or table 102 on which the box toe applying machine 40 is supported, above the table, by means of supporting brackets 104, 104. Also supported on the table 102 are two upwardly extending column members 106 and 108. Associated with the column 106 is a vamp loading member, indicated generally by the reference character 110, `and associated with the other column 108 is a vamp unloading member, indicated generally by the reference character 112.

The vamp loading member comprises a hollow box-like body portion 120, FIG. 2, formed on the outer end of a hollow arm 122 and having two rearwardly extending tubular portions 124, 124. Telescopically fitted into each of these two tubular portions is a tubular exten-sion 126 having a foot portion 12S. At its inner end, the arm 122 is secured to a box-like member 130 which is carried by the upper end of a shaft 132 journaled in upper and lower bearing members formed on the column 108, FIG. l. The upper side of this box-like member is provided with an opening 136 which establishes communication between a passage 138 in the hollow arm 122 and the interior of a vacuum chamber 140 mounted on the top of the column 108, a suitable .sealing means being interposed between the member 130 and the lower side of this chamber. A hose 144 connects this chamber to a vacuum source under the control of a valve, not shown, but which is adapted to be opened and closed by means of a fluid pressure operated piston 150, contained within a cylinder 152, FIG. 7. Opening through the lower side of the body 120 are three suction passages and similar passages 162 are provided in the two feet 128, 128 on the extensions 126, 126. As will be readily understood, when the chamber 140 is connected to the vacuum source, a strong suction force will be exerted at the openings 160, 162.

The unloading member 112 comprises a hollow body portion carried on the outer end of a hollow arm 172 which is secured at its inner end to a box-like member 174, corresponding to the box-like member 130 which is associated with the arm 122. This box-like member is carried on the upper end of a shaft 176, journaled in upper and lower bearing members formed on the column 108, FIG. 1. Opening through the lower side of the body 170 are two suction passages 178, 178 which are in communication, through the hollow arm 172 and box-like member 174 with a chamber 180 mounted on the upper end of the column 108 through an opening 182 in the member 174. A hose 182 connects this chamber to a vacuum source under the control of a valve, not shown, but which is adapted to be opened and closed by means of a piston 184 contained within a cylinder 186, FIG. 7. When this valve is opened, a strong suction force will be exerted at the passages 178, 178. Carried by the hollow body portion 170 is a sauce-like projection 188 of the shape shown in FIG. 3.

Secured to the shaft 132 is an arm 200, FIG. 5, and secured to the shaft 176 is a similar arm 202. Arm 200 is connected to one side of a T-shaped arm 204, by means of a link 206 while the arm 202 is connected to the other side of the arm 204 by means of a link 208. As indicated in broken lines, FIG. 5, as a result of rotation of the arm 204 in a counterclockwise direction through an angle of 180, the positions of arms 122 and 172 will be reversed. Thus, when the arm 204 is in the position shown in solid lines, FIG. 5, the vamp loading member 110 will assume the positions shown in FIG. 2, directly over the work supporting pad 28 on the table 20, while the vamp unloading member 112 will assume the position shown in FIG. 2, directly over a work receiving device to be described below. Now, when the arm 204 is moved to the position shown in broken lines in FIG. 5, the positions of the vamp loading and vamp unloading members will be reversed, as shown in FIGS. 3 and 4.

For effecting such oscillating movement of the arm 204, this arm is secured to a shaft 210 journaled in a bracket member 212 which is supported on the table 102, FIG. 5. Fast on this shaft is a pinion 214 which is in mesh with the teeth of a rack 216. This rack is adapted to slide along a guide surface 218, formed on the bracket 212, and has a widened portion which runs between two anti-friction rolls 220, 220 mounted on the table 102. At one end the rack 216 is connected to the rod 222 of a piston 224 which is contained within a cylinder 226, see also FIG. 7.

Also secured to the shaft 210, beneath the table 102, is a second arm 230 which is provided at its outer end with a cam surface 232. When the parts are in the positions shown in FIGS. 2 and 5, this cam surface engages the operating member 234 of a pilot valve 236 and shifts this valve to the position in which it is shown in FIG. 7. At the same time, the operating member 240 of another pilot valve 242 is engaged by a cam surface 244 formed on the rack 216 and this valve is shifted to the position shown in FIG. 7. Upon rotation of the arm 204 to the broken line position, FIG. 5, valves 236, 240 will be shifted to their other positions by means of operating springs, while the cam surface 232 will now engage the operating member 246 of a pilot valve 248 and shift this valve, against the resistance of its spring, away from the position in which it is shown in FIG. 7. The functions performed as a result of the above-mentioned shiftings of the pilot valves 236, 242 and 248 will be explained below.

Referring to FIGS. l and 6 of the drawings, there is supported on the table 102 a vamp stacking device, indicated generally by the reference character 300. This device includes an auxiliary table 302 mounted, by means of an undercarriage 304, for rectilinear sliding movement along guideways formed in a head portion 306. For effecting such sliding movement of the table 302, thus to adjust the lengthwise position of a stack of vamp portions V, located on the table by means of four adjustable guide rods 308, an adjusting screw 310, journaled on a portion of the head 306, is threaded through a boss 312 on the end carriage 304. The head portion 306 is carried on the upper end of a rod 316 which is slidably mounted in the bore 318 of a sleeve member 320 which is secured to the table 102 by means of a bracket 321.

Supported on an ear 322, extending outwardly from the sleeve member 320 is .a cylinder 324 within which there is a piston 326 having a downwardly extending piston rod 328. At its lower end, this rod is secured to the lower portion of an angular bracket member 330. At its upper end, this bracket is fastened to the rod 316 and carries a plate 332 on which there is mounted a cylinder 334. Within this cylinder there is a piston 336 having a rod 338 which extends upwardly and which is secured, adjacent to its upper end, to a boss 340, formed integrally with the sleeve 320 by means of a set screw 342.

The cylinder 334 and piston 336 therein constitute the operating elements of a hydraulic dash pot unit which serves to regulate the rate of upward movement of the -rod 316 and table by means of suitable check valves and flow control valves 350, 352 and 354, as diagrammati'cally illustrated in FIG. 7 wherein the piston 336, instead of the cylinder 334 is illustrated as the moving element. For limiting the extent of such upward movement of the table 302, when the uppermost vamp V thereof is nearly in contact with the lower surface of the body portion 120 and with the foot members 128, 128, a pilot operated valve 360 is associated with this hydraulic dash pot arrangement, see FIGS. 6 and 7. For actuating this valve, a solenoid operated pilot valve 362, FIG. 7, is provided having a coil adapted to be de-energized when a microswitch 364, mounted on the body portion 120, is opened.

This microswitch has an operating arm 366 which is connected to the upper end of a sensing linger 368, slidably mounted in guide openings formed in the body portion 120. As shown in FIG. 6, this sensing linger normally projects a short distance below the lower surface of the body portion 120 to an extent determined by a shoulder 370 thereon which is held yieldingly against the bottom wall of the body portion by a relatively light coil spring 372. Thus, when the table is moved upwardly by the piston 326, to bring the uppermost vamp portion V into contact with the sensing finger, this finger will be elevated to open the switch 364 thereby deenergizing the lcoil of pilot valve 362. Valve 360 will now be shifted by its spring to block lthe flow of luid from the lower end of cylinder 334, FIG. 6 (left hand end FIG. 7), thereby immediately arresting upward movement of the table 302. As shown in FIG. 7, the flow control valve 354 serves to regulate the supply of hydraulic fluid from a small reservoir 380` to the hydraulic dash pot mechanism.

Secured to and extending downwardly from the head portion 306 is an elongated bar member 390 formed with a laterally extending angularly disposed ange 392. When the head and auxiliary table 302 are in their lowermost positions, as shown in FIG. 6, the inclined surface on one side of this flange engages the operating elements 394, 396 of two pilot valves 398, and 400, respectively, see FIG. 7, and shifts these valves to the positions shown against the resistance of their respective return springs. A third pilot valve 402 is similarly shifted by the clamp 22 when it is in its up position.

The work receiving device, referred to above, comprises a llat table or platform 410 supported on the frame construction 100, in the inclined position shown, by means including a rod 420 and a clamp block 422, FIG. 1. Carried by the table and extending upwardly therefrom are four guide rods 424, arranged in the pattern shown, FIGS. l, 2, 4 and 5.

Without attempting to identify and explain in detail every control valve, `check valve, pilot valve, etc., included in the pneumatic diagram shown in FIG. 7, which embraces both the pneumatic system for operating the loading device shown in the upper portion of the diagram, and the pneumatic system for operating the box toe applying machine with which the loading device is associated, shown in the lower portion of the diagram, the operation of these two mechanisms will be outlined briefly below.

Pressure fluid is supplied to various pressure lines upon the manuel opening of a main valve 496, thus causing the several operating pistons to assume the positions shown in FIG. 8 and the operating elements to assume the positions shown in FIG. l. To start the loading mechanism and box toe applying machine in operation, a manual valve 500 is momentarily depressed. This causes a pilot operated valve 502 to shift and to admit pressure iluid to the left hand end of cylinder 226 thus causing piston 224 t0 move to the right and swing the loading member out from the position shown in FIG. l to the position shown in FIG. 4, while the unloading member 112 assumes the position shown in FIG. 3. Valves 236 and 242 will now be shifted from the positions `shown in FIG. 7 by their associated springs while valve 248 is shifted by the action of Icam 232 on its operator 246. A pilot valve 504 is now shifted to admit pressure fluid to the right hand end of the cylinder 324 (lower end in FIG. 6) thereby causing the vamp stacking device to move upwardly. This releases the valves 398, 400 for elevation by their associated springs to a line blocking position.

When the uppermost vamp V on the stacking device engages `and elevates the sensing finger 368, the normally closed switch 364 will be opened and after a predetermined time interval which may be varied by an adjustable potentiometer, indicated by reference character 36S, FIG. 9, the coil of the solenoid operated valve 362 will be deenergized. This valve is now shifted by its spring to dire-ct pilot pressure fluid to the Valve 360 which is closed immediately to arrest upward movement of the stacking device. Pilot pressure fluid is also directed to the valve 504 which is now shifted to ca-use the stacking device to move downwardly (cylinder 324 and piston 326) and the upper pilot line to valve 506 is connected to exhaust thus causing this valve to shift to a position to admit pressure uid to the right hand end of cylinder 152. The piston now moves to the left to open the vacuum line 144 leading to the loading device 110. The topmost vamp V is now picked up by the loading device which is immediately swung back to the position in which it is shown in FIG. 2 by the piston 224, placing the vamp over the pad 28 and beneath the clamp 22. The valve 242 is now opened to direct pilot pressure fluid to the lower pilot line to valve S06 thus shutting off the Vacuum line 144. Switch 364 is still being held open by the engagement of the vamp with the sensing finger so that a valve 510 is held in open position, to which it was moved by pilot pressure from valve 248, for directing pilot pressure fluid to a valve 512, associated with the cylinder 26 and the piston 24. The clamp 22 is now operated to clamp the vamp V on the pad 28, the operation of this clamp and the release of the vamp by the loading device occurring almost simultaneously.

As a result of the operation of the clamp 22, an automatic operating cycle of the box toe applying machine is initiated. Thus, when this clamp is closed, a valve 520 directs pilot pressure fluid to shift a valve 514 thus causing the work table to be operated to carry the vamp in under the applying device 40. This shifts the valve 516 to cause the applying device to be moved down by piston 50 to operative position which, in turn, shifts a valve 522 to direct pilot pressure fluid to the opposite end of the valve 514. The work table now moves outwardly and during this outward movement the applier device applies molten thermoplastic box toe material to the vamp. When the table completes its outward movement, a valve 524 directs pilot pressure to the other end of valve 512 thus causing the clamp to move to open position.

When the valve 516 was shi-fted to a position to cause a piston 50 to move the applier device down to operative position, pilot pressure fluid was directed to the valve 508 shifting this valve to a position to cause the piston 184 to open the vacuum line 182 leading to the unloading device 112. Accordingly, just as soon as the clamp opens, the vamp to which the box toe material had just been applied is picked up by the unloading member 112. In the meantime, the loading device 110 has `been swung out to the position shown in FIG. 4, the stacking device has been elevated, another vamp picked up by the loading device and the loading device is again swung into the position shown in FIG. 2, thus causing the unloading device to swing out to the position shown in FIGS. 1 and 2 whereupon the vacuum in line 182 is discontinued and the vamp V just operated on is deposited on the work receiving device 410.

The above operating cycle of the loading and unloading devices and the box toe applying machine will continue in the above manner until a stop valve 530 is operated, the supply of Vamps on the stacking device is depleted, or the vamp drops from the loading device and is not placed on the work table 20. When either of the latter two events occurs, the switch 364 is not held in open position by a vamp as the loading device is swung in to the position shown in FIG. 2. Therefore, the coil of solenoid valve 3o2 is energized and this valve is shifted to a position to -direct pilot pressure uid to the lower end of the valve 510 thus shifting this valve to a position for preventing the ow of pilot pressure to the upper end of the valve 512. Piston 24 is, accordingly, not operated to close the clamp and to open the valve 520 and the operation of the box toe applying machine is interrupted as is lalso the operating cycle of the loading and unloading mechanism, the parts coming to rest in the positions in which they are shown in FIG. 1 of the drawings.

As explained above, the shoe part supporting surface of the pad 28 of the work table 20 lalways lies in the predetermined horizontal plane X-X, FIG. 7, when there is no shoe part clamped thereon. It will also be apparent that the two pick-up devices, i.e., the vamp loading member 110 and the vamp unloading member 112, which are mounted for swinging movements about axes perpendicular to the plane of the work table, each operate in the same predetermined horizontal plane (see Y-Y, FIGS. 6 and 7) which is parallel to the plane X-X of the work table. The parts are so arranged that the former plane is just slightly above the latter so that the shoe parts are presented to the work table parallel to and just a little above the upper surface of the pad 28. Thus, each shoe part V is presented to the machine directly over the upper surface of the pad 28 and beneath the clamp member 22 so that when vacuum to the loading member is cut off the shoe part will drop on the pad just before the clamp member 22 is actuated. Similarly, the shoe part engaging surface of the unloading member 112 is located immediately above the shoe part V, after the table 20 has been returned to its starting position, and closely adjacent thereto vertically so that the shoe part is picked up nicely when the vacuum is turned on in the member 112, which occurs just after the clamp member 22 is moved upwardly to release the shoe part. With this arrangement, variations in the thickness of the shoe parts are of no consequence and the arms 122 and 172 carrying the loading and unloading members, respectively, may be mounted rigidly and unyieldingly.

As is indicated above, the elevation of the sensing finger 368 effects the following three actions: The upward movement of the stacking device 300 is terminated, the vacuum line 144 leading to the loading device 110 is opened and the stacking device starts its downward movement. The uppermost vamp V on the stacking device comes under the influence of the vacuum pickup just as soon as the line 144 is open so that this vamp is picked up before the stacking device moves downwardly far enough to remove the uppermost vamp from the scope of influence of the vacuum pickup device. By varying the time interval between initial contact and movement of the sensing finger 368, 'by the uppermost vamp V, by means of the adjustable potentiometer 365, `and the shifting of valve 362, the spacial relationship between the uppermost vamp and the pickup member, at the time the three aforementioned actions occur, can be varied to suit different vamp materials.

With Vamps made of -relatively porous material, such, for example, as canvas or other fabrics, this time interval may be decreased so that the uppermost vamp is spaced quite widely from the pickup device when the vacuum line is open. This distance is so selected that the action of the vacuum pickup is just sufficient to lift the uppermost vamp from the stack without, at the same time, disturbing the vamp immediately beneath it. With less pervious materials, the time delay interval may be lengthened and the space between the uppermost vamp and the pickup device, when the three mentioned actions occur, correspondingly decreased so that only the uppermost vamp is picked up. In all cases, and even when the time delay is set at a maximum, `the upward movement of the stacking device is arrested before, or just as the uppermost vamp comes into contact with the pickup device and before any upward pressure is exerted thereon. Accordingly, and since the sensing finger operates independently of the pickup member, the loading device can lbe rigidly supported for movement in the plane Y-Y, which, as already explained, is parallel to and spaced slightly above the plane X-X of the work supporting pad 28.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for oper-ating on shoe parts having operating elements, a work supporting table and mechanism operable in an automatic operating cycle to effect relative movements of the operating elements and the table to cause a shoe part thereon to be presented to the operating elements, the elements to operate on the shoe part and the table to return to a starting position, the combination of a Shoe part handling mechanism and means for causing said mechanism to place shoe parts, successively, on the table, then to initiate an automatic operating cycle of the machine and finally to remove each shoe 9. part from the table after the table has returned to its starting position at the completion of said operating cycle.

2. In a machine for operating on shoe parts the combination as set forth in claim 1 wherein there is provided a shoe part stacking device and a shoe part receiving device and wherein power operated means a-re provided for causing said mechanism to pickup shoe parts, successively, from said stacking device, place each shoe part on the work table of the machine, then to initiate an operating cycle of the machine and finally to remove each part from the table, after the table has returned to starting position and deposit it on the shoe part receiving device.

3. In a machine for operating on shoe parts the combination as set forth in claim 2 wherein said shoe handling mechanism comprises a pair of shoe part handling members operable, respectively, in time relation to the operation of the machine, to pick up a shoe part from the stacking device and place it on the table and to pick up a shoe part from the table and deposit it on the shoe part receiving device, power means for operating said shoe part handling members, means for initiating an automatic operating cycle of the machine in response to the actuation of said first named shoe part handling member to place a shoe part on the table and means for initiating action of the other shoe part handling member upon return of the table to starting position.

4. A machine for operating on shoe parts as set forth in claim 3 wherein said shoe part handling members each comprise a pickup device carried by an arm mounted for swinging movement about an axis perpendicular to the plane of the work table of the machine and means for swinging said arms to cause them alternately and in succession to assume positions directly over the work table and over the said stacking vdevice and receiving device, respectively.

5. A machine for operating on shoe parts as set forth in claim 4 wherein said shoe part handling members each comprise a vacuum pickup device.

6. In a machine for operating on shoe parts having operating elements, a work supporting table and mechanism operatable in an automatic operating cycle to effect |relative movements of the operating elements and the table to cause a shoe part thereon to be presented to the operating elements, the elements to operate on the shoe part and the table to return to a starting position, the combination of a shoe part stacking device, a shoe part handling member operable in a predetermined plane parallel to and spaced slightly above the plane of the Work table to pick up a shoe part from the stacking device and place it on the work table, said stacking device being mounted for reciprocoating movements to present the uppermost shoe part of a stack of shoe parts thereon to said shoe part handling member, means for reciprocating the stacking device and means for arresting movement of the stacking device toward the shoe part handling member when the uppermost shoe part thereon reaches a predetermined heightwise position relative to and spaced from said shoe part handling member.

7. A machine for operating on shoe parts as set forth in claim 6 wherein said means for arresting heightwise movement of the stacking device includes a movable control element actuated by said uppermost shoe part on the stacking device.

8. A machine for operating on shoe parts as set forth in claim 6 wherein the means for arresting heightwise movement of the stacking device includes a control element having a feeler adapted to be contacted by the uppermost shoe part yas the stacking device moves upwardly toward the shoe part handling member.

9. In a machine for operating on shoe parts having operating elements, a Work supporting table and mechanism operable in an automatic operating cycle to effect relative movements of the operating elements and the table to cause a shoe part thereon to be presented to the operating elements, the elements to operate on the shoe part and the table to return to a starting position, the combination of a shoe part stacking device, a shoe part receiving device, a shoe part handling mechanism, power operated means for causing said mechanism to pick up shoe parts, successively from said stacking device, place each shoe part on the work table of the machine, initiate an operating cycle thereof and remove each shoe part from the table, after it has returned to its starting position, and deposit the shoe part on the shoe part receiving device, and control means for interrupting the operation of said shoe part handling mechanism, when no shoe part is picked up from the stacking device by the shoe part handling mechanism, or is placed on the Work table by said mechanism prior to the initiation of an automatic operating cycle of the machine.

10. Apparatus for loading work pieces into a machine having a work piece supporting member provided with a flat work piece receiving surface, a stack holder mounted adjacent to the machine for reciprocating movements along a path perpendicular to the plane of said work piece receiving surface, a loading device having a pickup member disposed in a plane corresponding to the plane of said work piece receiving surface and mounted for movement between a pickup position over the stack holder and a loading position over the Work supporting member, means for reciprocating said stack holder to cause it to move toward the loading device when the latter is in said pickup position, controlmeans for arresting movement of the stack holder toward the loading device including a sensing member operable independently of the pickup member and movable relatively thereto in response to contact with the uppermost work piece on the stack holder.

11. Apparatus as set forth in claim 10 wherein fluid pressure actuated means are provided for reciprocating the stack holder and wherein said control means comprises a valve shiftable to a position for arresting movement of the stack holder and means operable in response to movement of the sensing member for shifting said valve to arrest movement of the stack holder.

12. Apparatus as set forth in claim 10 wherein a variable time delay device is provided for varying the interval between movement of the sensing member and the arresting of movement of the stack holder toward the loading device and accordingly the spacial relationship between the uppermost work piece and said pickup member when movement of the stack holder is arrested.

13. Apparatus as set forth in claim 11 wherein a variable time delay device is provided for varying the interval between movement of the sensing member and the shifting of said valve and accordingly the spacial relationship between the uppermost Work piece and the pickup member when movement of the stack holder is arrested.

14. Apparatus as set forth in claim 11 wherein said valve operating means includes a solenoid adapted to shift the valve to a position to effect upward movement of the stack holder and a spring for shifting the valve to a position to arrest such upward movement, a switch for controlling the flow of electrical energy to the solenoid and adapted to be opened in response to movement of the sensing member thereby to de-energize the solenoid and effect shifting of the valve by said spring to a position to arrest movement of the stack holder.

15. Apparatus as set forth in claim 14 wherein a variable electrical time delay device is interposed between said switch and said solenoid for varying the interval between movement of the sensing member and the shifting of said valve to arrest movement of the stack holder and accordingly the spacial relationship between the uppermost work piece and said pickup member when movement of the stack holder is arrested.

16. Apparatus for loading work pieces into a machine having a work piece supporting member provided with a flat work piece receiving surface, a stack holder mounted adjacent to the machine for reciprocating movements along a path perpendicular to the plane of said work piece receiving surface, a loading device having a vacuum pickup arranged in a plane corresponding to the plane of said work piece receiving surface and mounted for movement between a pickup position directly over the stack holder and a loading position directly over the work supporting member, means for reciprocating said stack holder to cause it to move toward the loading device when the latter is in said pickup position, a valve for controlling the action of said vacuum pickup member, control means for arresting movement of the stack holder toward the loading device and for actuating said vacuum controlling valve including a sensing member operable independently of the loading device and movable relatively thereto in response to contact with the uppermost work piece on the stack holder.

17. Apparatus as set forth in claim 16 wherein uid pressure actuated means are provided for reciprocating the stack holder and for actuating said vacuum controlling valve and wherein said control means comprises a valve for arresting movement of the stack holder means operable in response to movement of the sensing member for shifting said valves to arrest movement of the stack holder and to supply vacuum to said pickup devices.

18. Apparatus as set forth in claim 16 wherein a variable time delay device is provided for varying the interval between movement of the sensing member and the arresting of movement of the stack holder toward the loading device and the supplying of vacuum to said pickup device and accordingly the spacial relationship between the uppermost work piece and said pickup member when movement of the stack holder is arrested and vacuum is supplied at said pickup device.

19. A machine as set forth in claim 17 wherein a variable time delay device is provided for varying the interval between movement of the sensing members and the shifting of said valves and accordingly the spacial relationship between the uppermost Work piece and the pickup member when movement of the stack holder is arrested and vacuum is supplied to said pickup member.

20. Apparatus as set forth in claim 17 wherein said valve operating means includes a solenoid adapted to shift the valve to a position to effect upward movement of the stack holder and a spring for shifting the valve to its other position for arresting upward movement of the stack holder, a switch for controlling the ow of electrical energy to said solenoid and adapted to be opened in response to movement of the sensing member thereby to de-energize the solenoid to arrest movement of the Stack holder and to supply vacuum to said pickup member.

21. Apparatus as set forth in claim 17 wherein a variable electrical time delay device is interposed between said switch and said solenoid for varying the interval between movement of the sensing member and the shifting of said valves to arrest movement of the stack holder and to supply vacuum to said pickup member and accordingly to vary the spacial relationship between the uppermost work piece and said pickup member when movement of the stack holder is arrested and vacuum is supplied to said pickup member.

References Cited UNITED STATES PATENTS 1,261,026 4/1918 Hogue 271-26 2,624,248 6/1958 Baker et al. 93-51 3,031,906 5/1962 Holman 83-94 3,147,500 9/1964 Ralphs 12--1 2,063,578 1l/l962 Millar 12--1 X PATRICK D. LAWSON, Primary Examiner. 

